IMO you over-state how important it is to finish 2nd rather than 3rd. We're so far away from Chelsea I don't think they'd have been looking over their shoulder at us either way.
We'd won 9 games out of 10 - the end of a longer good run, we're actually closer to Chelsea than we were after 12 games - to get us in a position where 2nd was in our hands.
We slipped up in one game so now we'll probably finish 3rd. If that slip was the difference between 1st and 2nd then I would see it as a failure, as it is it's not something I'm going to over-analyse be overly critical about. There is no actual difference between 2nd and 3rd, both qualify us automatically for the CL. Had we slipped to 4th and another qualification then I'd have seen more of a problem.
We didn't fail at the final hurdle in last year's Final. We nearly did of course, but we got there. Let's see what we do this year in the final. I don't care how we scored at OT. ManYoo got a lucky deflection in the game at the Emirates. These things happen. From the highlights I saw we deserved our point. You say it would surprise you if the other teams slipped up but apart from Chelsea they all must have done or we wouldn't be anywhere near them after our start.
One win against the gypos and a cup win against Utd is NOT what I view as success, if those results were in the middle of a season when we win nothing and finish mid-table then they would be meaningless. In a season where we win the Cup, if we do, and finish the 3rd then they do give me some hope that we can win games on the big occasion.
Wenger will keep making the same mistakes, but IMO overall he's doing more right than wrong. The main point I'm tryig to make is that the next bloke will just make different mistakes and those mistakes may well lead to a worse outcome. I can sympathise with the view that we need to try something different though.